It is known, in principle, to provide recognition or detection of flame events in modern technology, for example, in industrial production plants. After such a detection of a flame event, an alarm may possibly be generated. The presence of corresponding detector systems in defined areas is sometimes even required by law.
For example, radiation detectors, which especially monitor the surrounding area of the radiation detector for the occurrence of a radiation signature that is characteristic of flame events, especially preferably in the infrared spectral range, may be used for the detection of flame events. Flame events can be detected very rapidly, often within 300 msec or faster, and, in addition, with a low error rate in most cases. Such a radiation detector is known, for example, from U.S. Pat. No. 5,375,159 (the entire contents of U.S. Pat. No. 5,375,159 are incorporated herein by reference). However, a drawback in such radiation detectors is that they are only configured for the global monitoring of a detection area, so that a flame event is detected as soon as such a flame event occurs in the detection area of the radiation detector. Radiation detectors thus cannot be used or can be used at least only on a limited basis, in areas, in which planned flame events, for example, torching and/or flares, are provided.
Further known detectors for the detection of flame events are camera detectors, which record sequences of images, for example, in the visual and/or infrared spectral range. As soon as an indication of a flame event is recognized in one of the images, these sequences of images can be subjected to a downstream image analysis, in which a flame event can be recognized reliably and with low error rate especially by means of an image-by-image analysis. This precise image analysis is often time-consuming, so that, especially in comparison to radiation detectors, camera detectors can provide a reliable detection of a flame event only after a certain time, often several seconds. In addition to this drawback of a slow detection rate, camera detectors have, however, the advantage that in the images recorded by the camera detectors, areas can be excluded from the image analysis and thus from the monitoring for flame events. Such flame cameras are, known, for example, from U.S. Pat. No. 6,696,958 as well as U.S. Pat. No. 7,609,852 (the entire contents of U.S. Pat. No. 6,696,958 as well as U.S. Pat. No. 7,609,852 are incorporated herein by reference).